<html>
<head>
<script>
  function updateColor() {
    document.getElementById("updateColorControl").style.backgroundColor = "red";
    jsObserver.notifyJava();
  }
</script>
<style>
  body {
    margin: 0px;
    padding: 0px;
  }
  #updateColorControl {
    height: 100%;
    width: 100%;
    padding: 0px 0px;
    background-color: blue;
  }
</style>
</head>
<body>
<button id="updateColorControl" autofocus onclick="updateColor(); return false"></button>
</body>
</html>
